So I updated to 13.5, started an Win 10 VM that was running just fine in 13.0.2 and get this error (in German) :

"serialo: Parameter „serialo.fileType" weist einen ungültigen Wert „thinprint" auf."

Looks like 13.5 dropped support for this value (or added a check that 13.0.2 did not have). What's the background to this? Why do I have "thinprint" in the vmx anyway (never printed anything from that VM, nor set up printers, IIRC).

If an update drops a feature, it should know about this and handle the case by itself. Or at least suggest a solution or workaround (delete from vmx? change to what other value? Any consequences inside the VM? ...). Not just pop a technical error in my face...